This Camera Calculator finds the Lens Focal Length From the Target Field of View

Camera Lens Effective Focal Length Calculator

A Camera Focal Length Calculator. This Calculates a Lens EFL for Cameras.
A Camera Focal Length Calculator. This Calculates a Lens EFL for Cameras.

This effective focal length calculator helps you select a lens to use with your camera. The calculator takes your target field of view (angle of view) and camera specification then provides the required lens EFL.

The calculator uses the camera lens focal length equation. This formula is different than the lens maker's equation which is intended for simple thin lens elements.

The Optical Effective Focal Length (EFL) should not be confused with the Mechanical Back-Focal Length (BFL). The EFL determines the field of view of the camera while the BFL determines whether a lens will focus on a camera.

Read Our Camera Calculator & Optics Design Page, or Click below Use our Other Camera Calculators

Camera Field of View Calculator. FoV Calculator
Camera Depth of Field Calculator. DoF Calculator.
Camera Angle of View Calculator for Camera Lens Selection. AoV Calculator.

Here are a Few M12 Lenses. Search all 50+ Using Our M12 Lens Calculator

190°@5.7mm Fisheye M12 Lens

CIL290-F2.2-M12A660

190°@5.7mm Fisheye M12 Lens

Low Distortion 2.2mm M12 Lens

CIL023-F2.2-M12A650

Low Distortion 2.2mm M12 Lens

GoPro 3.0mm M12 Lens

CIL331-F2.5-M12B650

GoPro 3.0mm M12 Lens

Low Distortion 1.8mm M12 Lens

CIL018-F2.8-M12A650

Low Distortion 1.8mm M12 Lens

200°@6.3mm Fisheye M12 Lens

CIL219-F2.5-M12A650

200°@6.3mm Fisheye M12 Lens

We Also have Cost Effective 12MP+ C-Mount Lenses for Machine Vision and Factory Automation.

135° 4K+ low distortion M12 lens for IMX335 and AR0521
135° 4K+ low distortion M12 lens for IMX335 and AR0521
135° low distortion S-Mount Lens
No Distortion Wide Angle M12 Lens
CIL018-F2.8-M12A650
Low Distortion 1.8mm M12 Lens
$39.00
200° M12 Fisheye Lens
200° M12 Fisheye Lens
200° Mini Fisheye Lens
Mini M12 Fisheye Lens
CIL219-F2.5-M12A650
200°@6.3mm Fisheye M12 Lens
$79.00
5mm M12 Lens for IMX334
5mm M12 Lens for IMX334
5mm M12 Lens IMX334
5mm S Mount Lens IMX334
CIL046-F2.0-M12A650
IR Corrected 4.4mm M12 Lens CIL046
$79.00
Wide Angle Waterproof M12 Lens
Wide Angle Waterproof M12 Lens
IMX678 sturdEcam genicam GMSL lens
Stereocam
CIL341-F2.0-M12A650
Wide-Angle 4mm M12 Lens
$79.00
8mm M12 Lens CIL078 Nvidia Camera
8mm M12 Lens CIL078 Nvidia Camera
8mm M12 Lenses for Nvidia Camera
8mm S Mount Lens for Nvidia cameras
Low Distortion 7.8mm M12 Lens
CIL078-F2.0-M12A650
Low Distortion 7.8mm M12 Lens
$59.00
Telephoto 12mm M12 Lens
Telephoto 12mm M12 Lens
Telephoto M12 Lens 12mm
Arducam usb cameras Telephoto 12mm M12 Lens
Telephoto 12mm S-Mount Lens
CIL125-F2.4-M12A650
Telephoto 12mm M12 Lens
$39.00

What's Your Application? Our Lenses Cover the Spectrum.

Wide-Angle 4.5mm M12 Lens

CIL344-F1.9-M12B660

Wide-Angle 4.5mm M12 Lens

188°@6.6mm IP67 M12 Fisheye

CIL222-F2.0-M12A650

188°@6.6mm IP67 M12 Fisheye

Mobile Robotics?

Find a low F# or low distortion lens to optimize your computer vision.

Factory Machine Vision?

Our cost-effective compact C-Mount lenses are designed for up to 1.1"~1.2" format global shutter sensors.

230°@4.5mm Fisheye M12 Lens

CIL213-F2.3-M12A660

230°@4.5mm Fisheye M12 Lens

Large Format 5.5mm M12 Lens

CIL056-F2.4-M12ANIR

Large Format 5.5mm M12 Lens

Intelligent Everywhere?

Our low distortion lenses with multiple F# can be used to optimize your depth of field.

Surveillance?

Our fisheye and IR Corrected lenses are suitable for doorbell cameras and active IR illuminated scenes.

200°@5.7mm IP67 Fisheye M12 Lens

CIL217-F2.7-M12A650

200°@5.7mm IP67 Fisheye M12 Lens

Telephoto 12mm M12 Lens

CIL125-F2.4-M12A650

Telephoto 12mm M12 Lens

Ingress Protected 7.8mm M12 Lens

CIL079-F2.0-M12A650

Ingress Protected 7.8mm M12 Lens

IP67 12mm M12 Lens

CIL120-F2.4-M12A650

IP67 12mm M12 Lens

Does it Require Getting Dirty?

Our IP67 and IP69K lenses are suitable for applications exposed to the environment.

Aerial Robotics?

Our tiny lenses are ideal for collision avoidance and object recognition.

Telephoto 12mm M12 Lens

CIL125-F2.4-M12A650

Telephoto 12mm M12 Lens

Telephoto 35mm M12 Lens

CIL350-F2.4-M12ANIR

Telephoto 35mm M12 Lens